Threading chuck

ABSTRACT

A threading chuck for use with a machine tool has a pair of relatively rotatable, coaxial elements, one of the elements having a threading tool secured thereto. The other element is mounted on the work axis of the machine. A clutch is interposed between the elements and is adapted, when engaged, to hold the elements against relative rotation. However, when the clutch is released, the element carrying the threading tool is permitted to rotate relative to the other element, thereby discontinuing the threading operation.

United States Patent {72} Inventor I Raymond L. L511 1740 Berry Road,independence, Mo. 64057 [21] Appl. No. 764,829 [22] Filed Oct. 3,1968[45] Patented Aug. 17, 1971 [54] THREADING CHUCK 6 Claims, 12 DrawingFigs.

[52] U.S.C1 10/89, 10/129,10/135,10/14l [51] Int. 823g l/00, 823g 5/06,823g 5/14 [50] FieldotSeu-eh ..lO/89,89 F, 89 H, l29, 129 P, 141, 141 H,135

[561 References Cited UNITED STATES PATENTS 974,239 11/1910 Dalton 10/891,974,345 9/1934 Scholtes 10/89 2,244,143 6/194] Dowler. l0/1352,540,513 2/1951 Dodd 10/135 2,606,431 8/1952 Elgin 10/135 2,729,0761/1956 Thomson 1. lO/l35 3,214,773 11/1965 Benjaminetal. 10/135 FORElGNPATENTS 133;133 9/1919 GreatBritain...... lO/89 350,516 6/1931GreatBritain.... 10/89 663,102 12/1951 GreatBritain 10/89 PrimaryExaminer-Charles W. Lanham Assistant Examiner-J3. M. CombsAttorney-Schmidt, Johnson, Hovey & Williams Pmmmwmsn 13.599260 SHEET 1BF 2 INVENH )R Raymond L Leah THREADING CHUCK This invention relates toa threading chuck for use with a machine tool.

When fabricating material, it is often desirable to form exteriorthreads on cylindrical elements at a point in close proximity to ashoulder. However, this has not heretofore been practical withoutruining the workpiece, or in certain instances, the machine itselfsince, in prior art devices, there is no way to quickly discontinue thethreading operation when the threading die engages the shoulder. Formerdevices rely upon the operator to stop power to the machine as the toolapproaches the shoulder but this is unsatisfactory because it is verydifficult to disconnect the machine at exactly the right moment.Furthermore, a member must often be threaded over a specified lengthwhich is also very difficult to accomplish using prior art devicessince, as discussed above, the only way to stop the threading operationis to disconnect power to the machine.

Threading blind openings is also troublesome using heretofore availabledevices if the entire extent of the opening is to be threaded since theoperator must discontinue power to the machine precisely at the instantthat the tap reaches the bottom of the opening.

It is, therefore, an important object of this invention to provide adevice for holding a threading tool that can be quickly and easilymounted on the work axis of existing machine tools.

Another important object of this invention is to provide a deviceenabling the operator to have better control over the threadingoperation, enabling the threads to be started and discontinued asdesired.

Still another important object of this invention is to enable blindopenings to be tapped throughout their entire length up to a shoulderwith a member of larger diameter.

Another important object of this invention is to provide a device thatis able to accurately gauge and control the length of threads beingturned on the workpiece. In the drawings:

FIG. 1 illustrates the threading chuck of my present invention mountedon the work axis of an engine lathe;

FIG. 2 is a front elevational view of the chuck of FIG. 1;

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG.

FIGS. 4, 7 and 8 are cross-sectional views taken along lines 4-4, 7-7and 8-8 respectively of FIG. 3;

FIGS. and 6 are views similar to FIGS. 3 and 4 respectively, but showingthe threading chuck with the clutch thereof engaged;

FIG. 9 illustrates a tapping tool for use with my threading chuck;

FIG. 10 illustrates an adapter for use with my invention that enables asmaller threading die to be used with my chuck than that illustrated inFIG. 3;

FIG. 11 is a view illustrating a shank for use with my threading chuck;and

FIG. 12 illustrates the shank of FIG. 11 in use with my threading chuck.

Referring to FIGS. 2-8, a threading chuck has a pair of relativelyrotatable, coaxial, sleevelike elements 22 and 24. Element 22 has a tollholder 26 mounted on one end thereof for receiving and supporting athreading tool such as the die 28 of FIG. 3 or the tap 30 of FIG. 9.Threading tools 28 and 30 are retained in place in the holder 26 bysetscrews 32.

Element 24 has a shank 34 inserted therein having keys 36 engagingmating channels 38 in the element 24, thereby holding the shank 34against rotation relative to the element 24, but permitting chuck 20 toslide along shank 34. The end 40 of shank 34 is adapted to be mounted ina tailstock 42 of an engine lathe 44 as illustrated in FIG. 1. Shank 34is a solid bar having an enlargement or stop 35 thereon.

A clutch 46 is interposed between the elements 22 and 24 and is adapted,when engaged, to hold the elements against relative rotation. Clutch 46includes a first set of discs 48 coaxial with the elements 22 and 24,having keys 50 engaging corresponding channels 52 in the element 22.Keys 50 prevent the discs 48 from rotating relative to the element 22,but permit the discs to slide axially therealong. A second set of discs54 are rotatable relative to the element 22 but are flattened at 56 toengage corresponding flattened portions 58 on the elements 24. Theengagement of the flats 56 with the flat portions 58 prevents the discs54 from rotating relative to the element 24, but permits them to slideaxially therealong. Discs 48 and 54 are interposed between a bearingring 60 carried by element 22 and a nut 62 carried by the element 24.Threads 64 on the nut 62 are in mesh with corresponding threads on theelement 24, enabling nut 62 to be moved along element 24 toward and awayform the ring 60. A tubular member 66 is secured to the nut 62 forrotating the latter. Nut 62 is yieldably biased away from the ring 60 bythe resilient member or spring 68 which interconnects the nut 62 and acollar 70 rigidly secured to the element 24 by one or more setscrews 71.

Spring 68 is secured to nut 62 through an adjusting washer 73. Screws 75extend through arcuate slots 77 on washer 73 and into the nut 62. Oneend of the spring 68 is received by a hook 79 on the washer 73, theother end of the spring being fastened to the collar 70. Upon assemblyof the chuck 20, tension in spring 68 may be adjusted by rotating washer73 relative to the nut 62 and then tightening screws 75 to hold thewasher in position.

In FIG. 10 an adapter piece 72 is illustrated that enables a threadingdie (not shown) smaller than the die 28 illustrated in FIG. 3 to be usedwith the threading chuck 20. Setscrews 32 engage the corresponding flats74 in the adapter 72 to hold the same in the tool holder 26. The smallerthreading die (not shown) can be inserted in the opening 76 of theadapter 72 and setscrews 81 tightened against the die to hold the samein place.

Tap 30 is held in a chuck 78 which is inserted inthe tool holder 26, thesetscrews 32 being tightened against a pair of flats 80 to hold thechuck 78 in place. An adjustable cap 82 on the chuck 78 permits adifferent sized tap (not shown) to be inserted therein.

Referring now to FIGS. 11 and 12, a shank 84 is illustrated that may beused in the threading chuck 20 interchangeably with the shank 34 andenables the threading chuck to be used with a turret lathe or with amachine tool having a vertical work axis, such as a drill press or avertical milling machine. Shank 84 has an interior bore 86, an enlargedportion 88, and has keys that engage the channels 38 in element 24. Acap 92 has interior threads that mesh with the threads on the element 24and holds the enlarged portion 88 of shank 84 tightly against one end ofthe element 24.

In operation, end 40 of shank 34 is mounted in the tailstock 42 ofanengine lathe, and the threading chuck 20 is inserted thereupon.Tailstock 42 is moved forwardly until the threading tool 28 secured inthe holder 26 is in a disposition adjacent the outer end 93 of aworkpiece 94 to be threaded. The operator then grasps the knurledtubular member 66 and twists the same in a direction causing the nut 62secured thereto to rotate on the element 24 in a direction toward thebearing ring 60. Nut 62 engages the clutch 46 by forcing the discs 48and 54 against each other and against the ring 60. Since the discs 48alternate with the discs 54, when the nut 62 moves the discs together,the same will frictionally engage with each other thereby holdingelement 22 against rotation relative to the element 24. The operatorthen slides the threading chuck 20 along the shank 34 while holding thesleeve 66 in the rotated position until the chuck 20 engages the frontend of the workpiece 94 and begins to produce threads thereon.

After a few threads are cut on the workpiece 94 the interaction of thedie with the workpiece will automatically slide the chuck 20 along theshank 34 as long as the operator maintains the member 66 in a rotatedposition. If at any time during the threading operation it is desirableto cease producing threads on the workpiece the operator merely releasesthe member 66, at which time the spring 68 rotates the nut 62 away fromthe ring 60, thereby permitting the discs 48 and 54 to rotate relativeto each other. Upon disengagement of the clutch 46, element 22 willrotate with the workpiece relative to the element 24 which is heldagainst rotation by the shank 34. When the threads being produced on theworkpiece 94 reach the shoulder 96, the operator may release the tubularmember 66, thereby disengaging the clutch and discontinuing thethreading operation. However, even ifthe operator continues to hold themember 66 in a position engaging the clutch 46, the additional force ofthe shoulder acting against the front face of the threading chuck 20will overcome the frictional force locking the discs 48 and 54 together.Thus, the threading operation is automatically discontinued before theworkpiece or the lathe is damaged.

lndicia (not shown) may be placed along the keyed portion of the shank34 to enable the operator to measure the length of the threads that heis producing on the workpiece. Before the threading operation begins,the tailstock 42 is moved to a position where the end 98 of shank 34engages the die 28. Then, as the threading operation proceeds and thethreading chuck 20 is moved along the shank 34, indicia on the shank 34will be exposed to indicate the length of threads that have beenproduced on the workpiece.

Use of shank 84 with the threading chuck 20 permits the same to be usedwith a turret lathe, drill press, or a vertical milling machine. Shank84 is inserted into the element 24 and the cap 92 locks shank 84 againstaxial movement relative to element 24. The shank end 100 can then belocked in the spindle of a drill press or vertical milling machine, orin the tailstock turret of a lather. As the chuck 20 is lowered againstthe workpiece, the upwardly acting force of the workpiece against thetool holder 26 will force the ring 60 carried by the element 22 intoengagement with the first of the discs 48 or 54. Further downwardmovement will force the discs 48 and 54 against the nut 62 and againsteach other, thereby holding the element 22 against rotation relative thethe element 24. Since the threading chuck 20 is being rotated in thespindle of the drill press or vertical milling machine, threads will beproduced on the workpiece. When it is desirable to cease producingthreads, the operator merely releases the pressure on the spindle,thereby releasing the clutch 46 and permitting the element 24 to turnrelative to the element 22. If the threading tool 28 engages a shoulderon the workpiece, the twisting force produced thereby will overcome thefrictional force between the discs 48 and 54 thus permitting element 22to rotate relative to the element 24 whether or not the pressure on theheadstock is also released. If a relatively long workpiece is to bethreaded, the threaded portion of the workpiece is received in the bore86 of shank 84. However, if a relatively short work piece is to bethreaded, a solid shank, such as the shank 34, may be used in place ofthe shank 84. Also, the shank 84 may be used with the threading chuck 20if the same is to be mounted in the tailstock of a lathe, but since thekey 90 is in the shank 84 is relatively short, the tailstock must becontinually advanced along the lather bed as the threading opera tionprogresses.

Although the operation of the threading chuck has been described using adie for producing external threads on a workpiece, a bore may bethreaded by using the tap 30 and chuck 78 in place of the die 28. Uponengagement of the tap 30 with the bottom of a bore. the clutch 46 willbe disengaged in a manner identical to that described above when the die28 engages a shoulder on a workpiece.

Thus, it can be seen that the threading chuck described above enablesthe workpiece to be threaded over a particular length or up to ashoulder. The threading chuck 20 enables the workman to have precisecontrol over the threading operation and enables him to stop and startthreads as he wishes. The invention therefore provides a device that notonly is highly useful but is also easily adaptable for use in existingmachine tools and may be quickly and easily removed and insertedthereupon.

Having thus described the invention, what I claim as new and desired tobe secured by Letters Patent is:

l. in a device of the kind described;

a pair of relatively rotatable, coaxial elements;

a clutch interposed between the elements, and adapted when engaged tointerconnect the elements for rotation together as a unit;

structure shiftably carried by one of said elements for movement to andfrom a position effecting engagement of said clutch;

a tubular member freely rotatable on the other of said elements andconnected with said structure for shifting the latter toward and awayfrom a position to effect engagement of the clutch; and

a resilient member interconnecting said structure with said one element,

said member yieldably biasing said structure away from the positioneffecting engagement ofthe clutch.

2. In a device of the kind described;

a pair of relatively rotatable, coaxial elements;

a clutch interposed between the elements, and adapted when engaged tointerconnect the elements for rotation between as a unit,

structure shiftably carried by one ofsaid elements for movement to andfrom a position effecting engagement of said clutch;

a tubular member freely rotatable on the other of said elements andconnected with said structure for shifting the latter toward and awayfrom a position to effect engagement of the clutch,

said clutch including a first set of discs held for rotation with saidone element and a second set of discs held for rotation with the otherof said elements the discs of the first set being alternately spacedwith the discs of the second set,

each ofsaid discs being slidable axially along the elements;

a bearing ring carried by said other element,

said structure including a nut on said one element movable toward andaway from said ring,

there being screw threads son said one element in mesh with the threadson the nut,

said discs being interposed between said nut and said ring whereby, uponmovement of the nut toward said ring, the discs of the first set will beforced against corresponding discs of the second set to lock theelements against relative rotation;

a collar secured to said one element; and

a resilient member interconnecting the nut and the collar for yieldablybiasing said nut away from said ring.

3. A chuck comprising:

a shank adapted to be held against rotation and against axial movement;

a first element shiftably carried by said shank for free, un-

restricted movement longitudinally on the shank in either direction;

means interconnecting said shank and said first element for preventingrotation of the latter relative to the shank;

a second element coaxially carried by said first element for movementwith the latter along the shank and for rotation of the second elementabout said axis relative to said first element;

tool-holding means on said second element adapted for carrying a tool tobe used on a rotating work product;

a clutch interposed between the elements and adapted when engaged tointerconnect the elements to resist said rotation of the second elementwith the work product to an extent topermit machining of said rotatingproduct as the elements advance along the shank as a unit in onedirection of movement thereof; and

manually operable structure on said first element freely shiftable intoand out of a position effecting engagement of said clutch while saidsecond element is rotating with the product for controlling the rotationof said second element.

4. A chuck as claimed in claim 3, wherein is provided a bearing memberon said first element remote from said struc- 75 ture for facilitatingsaid rotation of the second element.

the clutch by rotation of said tube.

6. A chuck as claimed in claim 3, wherein is provided a resilient memberinterconnecting said structure and said first element to yieldably biasthe structure out of said position.

1. In a device of the kind described; a pair of relatively rotatable,coaxial elements; a clutch interposed between the elements, and adaptedwhen engaged to interconnect the elements for rotation together as aunit; structure shiftably carried by one of said elements for movementto and from a position effecting engagement of said clutch; a tubularmember freely rotatable on the other of said elements and connected withsaid structure for shifting the latter toward and away from a positionto effect engagement of the clutch; and a resilient memberinterconnecting said structure with said one element, said memberyieldably biasing said structure away from the position effectingengagement of the clutch.
 2. In a device of the kind described; a pairof relatively rotatable, coaxial elements; a clutch interposed betweenthe elements, and adapted when engaged to interconnect the elements forrotation between as a unit, structure shiftably carried by one of saidelements for movement to and from a position effecting engagement ofsaid clutch; a tubular member freely rotatable on the other of saidelements and connected with said structure for shifting the lattertoward and away from a position to effect engagement of the clutch, saidclutch including a first set of discs held for rotation with said oneelement and a second set of discs held for rotation with the other ofsaid elements the discs of the first set being alternately spaced withthe discs of the second set, each of said discs being slidable axiallyalong the elements; a bearing ring carried by said other element, saidstructure including a nut on said one element movable toward and awayfrom said ring, there being screw threads son said one element in meshwith the threads on the nut, said discs being interposed between saidnut and said ring whereby, upon movement of the nut toward said ring,the discs of the first set will be forced against corresponding discs ofthe second set to lock the elements against relative rotation; a collarsecured to said one element; and a resilient member interconnecting thenut and the collar for yieldably biasing said nut away from said ring.3. A chuck comprising: a shank adapted to be held against rotation andagainst axial movement; a first element shiftably carried by said shankfor free, unrestricted movement longitudinally on the shank in eitherdirection; means interconnecting said shank and said first element forpreventing rotation of the latter relative to the shank; a secondelement coaxially carried by said first element for movement with thelatter along the shank and for rotation of the second element about saidaxis relative to said first element; tool-holding means on said secondelement adapted for carrying a tool to be used on a rotating workproduct; a clutch interposed between the elements and adapted whenengaged to interconnect the elements to resist said rotation of thesecond element with the work product to an extent to permit machining ofsaid rotating product as the elements advance along the shank as a unitin one direction of movement thereof; and manually operable structure onsaid first element freely shiftable into and out of a position effectingengagement of said clutch while said second element is rotating with theproduct for controlling the rotation of said second element.
 4. A chuckas claimed in claim 3, wherein is provided a bearing member on saidfirst element remote from said structure for facilitating said rotationof the second element.
 5. A chuck as claimed in claim 3, wherein saidstructure includes a nut threaded onto said first element, and whereinis provided a gripping tube secured to said nut and surrounding thelatter and said second element for effecting engagement of the clutch byrotation of said tube.
 6. A chuck as claimed in claim 3, wherein isprovided a resilient member interconnecting said structure and saidfirst element to yieldably bias the structure out of said position.